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  <title>Check if filesystem supports extended attributes</title>
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  <div id="layout-content"><div id="function.xattr-supported" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">xattr_supported</h1>
  <p class="verinfo">(PECL xattr &gt;= 1.0.0)</p><p class="refpurpose"><span class="refname">xattr_supported</span> &mdash; <span class="dc-title">
   Check if filesystem supports extended attributes
  </span></p>

 </div>
 <div class="refsect1 description" id="refsect1-function.xattr-supported-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>xattr_supported</strong></span>(<span class="methodparam"><span class="type">string</span> <code class="parameter">$filename</code></span>, <span class="methodparam"><span class="type">int</span> <code class="parameter">$flags</code><span class="initializer"> = 0</span></span>): <span class="type">bool</span></div>

  <p class="para rdfs-comment">
   This functions checks if the filesystem holding the given file supports 
   extended attributes. Read access to the file is required.
  </p>
 </div>

 <div class="refsect1 parameters" id="refsect1-function.xattr-supported-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>
    
     <dt>
<code class="parameter">filename</code></dt>

     <dd>

      <p class="para">
       The path of the tested file.
      </p>
     </dd>

    
    
     <dt>
<code class="parameter">flags</code></dt>

     <dd>

      <p class="para">
       <table class="doctable table">
        <caption><strong>Supported xattr flags</strong></caption>
        
         <tbody class="tbody">
          <tr>
           <td><strong><code>XATTR_DONTFOLLOW</code></strong></td>
           <td>Do not follow the symbolic link but operate on symbolic link itself.</td>
          </tr>

         </tbody>
        
       </table>

      </p>
     </dd>

    
   </dl>

  </p>
 </div>

 <div class="refsect1 returnvalues" id="refsect1-function.xattr-supported-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   This function returns <strong><code>true</code></strong> if filesystem supports extended attributes,
   <strong><code>false</code></strong> if it doesn&#039;t and <strong><code>null</code></strong> if it can&#039;t be determined (for example
   wrong path or lack of permissions to file).
  </p>
 </div>

 <div class="refsect1 examples" id="refsect1-function.xattr-supported-examples">
  <h3 class="title">范例</h3>
  <p class="para">
   <div class="example" id="example-2240">
    <p><strong>示例 #1 <span class="function"><strong>xattr_supported()</strong></span> example</strong></p>
    <div class="example-contents"><p>
     The following code checks if we can use extended attributes.
    </p></div>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br />$file&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #DD0000">'some_file'</span><span style="color: #007700">;<br /><br />if&nbsp;(</span><span style="color: #0000BB">xattr_supported</span><span style="color: #007700">(</span><span style="color: #0000BB">$file</span><span style="color: #007700">))&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #FF8000">/*&nbsp;...&nbsp;make&nbsp;use&nbsp;of&nbsp;some&nbsp;xattr_*&nbsp;functions&nbsp;...&nbsp;*/<br /></span><span style="color: #007700">}<br /><br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
    </div>

   </div>
  </p>
 </div>

 <div class="refsect1 seealso" id="refsect1-function.xattr-supported-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="function.xattr-get.html" class="function" rel="rdfs-seeAlso">xattr_get()</a> - Get an extended attribute</span></li>
    <li class="member"><span class="function"><a href="function.xattr-list.html" class="function" rel="rdfs-seeAlso">xattr_list()</a> - Get a list of extended attributes</span></li>
   </ul>
  </p>
 </div>

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